Apparatus for ironing laundry
BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus for ironing laundry, said apparatus comprising at least one semi-circular open dished bed provided with a double wall with feed and outlet opening for passage of a heating medium, such as steam, and a roll rotatably driven in each dished bed. 
     Such apparatus is known in different embodiments, but particularly with the dished bed construction. The type of heating medium is chosen depending on the construction used and, if steam is chosen, the danger of condensation in the dished bed must be prevented. Condensation that may occur has the drawback that the temperature distribution in the inner wall of the dished bed becomes uneven, which has a detrimental effect on the ironing process. This assumes a particularly significant character if more than one dished bed is employed in the apparatus. 
     SUMMARY OF THE INVENTION 
     The invention has for its object to provide an apparatus in which the above drawback is obviated and provides to this end an apparatus which is distinguished in that the outlet opening of a dished bed is placed in direct connection to the feed opening of the following dished bed. 
     The heating medium will therefore successively heat the dished beds connected in series, which requires a high flow speed for a good operation. This high flow speed prevents eventual condensation forming in the flow ducts in the dished bed wall. 
     Each dished bed wall is preferably embodied with flow ducts connected in series and extending in an axial direction. The flow speed is hereby increased still further and not only is condensation forming prevented as much as is possible but, in the case it should nevertheless occur, this condensation is immediately carried along with the steam to a water separator arranged in the system. 
     In accordance with a further development it is recommended that the water separator be placed directly by the outlet opening of a dished bed, whereby condensation is prevented from being carried along to the following dished bed. 
     In an apparatus wherein more than one dished bed are placed one after the other a bridge piece is normally arranged to guide the laundry out of the one dished bed and into the other, this bridge piece usually being heated. In this embodiment it is recommended according to the invention to feed the bridge with a steam line formed by the outlet line of the final dished bed. 
     In the case that a steam trap connected to a joint outlet line is arranged after each water separator and/or bridge piece, it is recommended according to the invention that a venting valve be arranged parallel to the final steam trap. Use of such a venting valve ensures that the whole system can be blown through, whereby collection of air or other noncondensing gases in the steam areas can be avoided with hundred percent certainty. 
     Vapor lock in the system can be prevented by arranging on the steam trap a venting line which leads to the steam line of the following element or to the venting valve. 
     The invention will be further elucidated in the figure description hereinafter of an embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a schematic view of an apparatus provided with two dished beds having rolls driven rotatably therein and provided with a bridge piece, and a flow diagram, 
     FIG. 2 is a perspective view of a dished bed used with the apparatus as in FIG. 1, 
     FIG. 3 is a perspective view, partly in section, of a detail of the water separator used with a dished bed as in section III of FIG. 2, 
     FIG. 4 is a perspective view of a detail as according to section IV of the dished bed wall in FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows two dished beds 1 having arranged therein rotatably driven rolls 2, the driving and construction whereof fall outside the scope of the invention. It is generally known that the dished bed 1 is double-walled, wherein the wall is heated by a medium to be further elucidated below, here superheated steam at a determined pressure and temperature. Placed between the dished beds 1 is a bridge 3, wherein it must be assumed that the inner wall of the dished bed 1 makes a smooth connection onto the outer wall of bridge 3 which in turn then connects smoothly onto the inner wall of the following dished bed. This serves to guide the laundry that is fed in the usual manner between the roll 2 and the inner wall of the dished bed 1, heated and therefore ironed and subsequently guided again via the bridge 3 into the following dished bed 1 to be subjected once again to an ironing operation. 
     The invention relates to the heating system for heating the inner wall of the dished bed 1. 
     From a heating source (not shown), for example a steam boiler, steam or a similar hot gas is carried via the feed line 5 to the two opposite upper edges of the dished bed 1. The wall of the dished bed 1 is embodied with lengthwise ducts which extend in axial direction and which are moreover connected to each other in series, which gives rise to a zigzag-like flow path, this being indicated with the arrows P 1 . The wall takes an exactly symmetrical form so that the outlet opening is located on the underside of the dished bed, which outlet is designated with the reference numeral 6. The steam line 6 leads to a water separator 7, of which the steam line 8 is fed through directly to the feed openings for the steam of the following dished bed 1, which are designated here with the numeral 5&#39;. The outlet 6&#39; of the dished bed leads to a second water separator 7&#39; of which the outlet steam line 9 leads to the bridge piece 3. The bridge piece 3 is provided with an outlet line 10 which leads directly to a common outlet line 11 for the condensate. 
     A steam trap 12 is arranged between the water separators 7&#39; and the common outlet line 11 as well as between the outlet line 10 and the common outlet line 11 of the bridge piece 3. 
     Arranged in parallel to the final steam trap is a venting valve 13. 
     In order to be able to vent the steam traps 12 a venting line is connected thereto which either leads to the outlet line 8 or 9 from the first water separator or the second water separator respectively or leads directly to the outlet line 10 coming from the bridge piece 3. 
     It will be apparent from the above discussed diagram that as a result of the series connection of the dished beds 1, a high steam speed can be maintained in the lines 6, 8, 9 and 10, which prevents condensation occurring in the axially directed lengthwise ducts in the dished beds 1. If this should nevertheless be the case the high flow speed will ensure that it is carried along to the water separators 7 located after the dished beds 1. 
     Venting can be carried out in simple manner via the venting valve 13 arranged as the final one in the system which ensures that all the air and other non-condensing gases will be removed from the system. The short-circuit line 14 provides venting of the steam traps 12. 
     FIG. 3 shows a detail of the underside of the dished bed 1 wherein the outlet opening of the outlet pipe 6 for the steam out of the lowest most central lengthwise duct in the double wall of the dished bed 1 is shown in detail. Before the steam outlet 6 are placed baffle plates 20 which form a labyrinth for collecting condensation that has been carried along out of the lengthwise ducts of the dished bed 1. The captured condensation is discharged into the condensation outlet 21 and 22. These lead to a common condensation outlet 23 which can be connected directly onto the condensation outlet 11 in FIG. 1. 
     The invention is not limited to the above described embodiment.